11: Biodiverity Flashcards
what is a general definition of a species
two organisms are in the same species if they are structurally similar and able to breed with each other produce fertile offspring
6 criticisms of the general definition of a species
1) naturally infertile organisms?
2) variation?
3) fossils?
4) 2 male organisms
5) asexual reproduction
6) fertile hybrids? wholphin
approximate for number of species on earth
3-100 million
how many species are named, how many unnamed?
1.7 million
500,000
what is variation
differences between organisms eg. appearance,behaviour, biochem
causes of variation
combination of genetic and environmental factors, (genetic- mutation and sexual reproduction)
what are two types of variations generally
discontinuous and continuous
who was the father of taxonomy
linnaeus
putting organisms into groups is…
classification
the science of classification is…
taxonomy
what is the smallest taxonomic group
species
what is the morphological species concept species definition
species is a group of organisms that are morphologically unique
what is the universal naming system linnaeus crafted?
binomial naming system
what is the first word in the binomial naming system? +feature
Genus (capital)
what is the second word in binomial naming system? +feature
species (lowercase)
when handwriting what must be remembered about binomial names
underline, italics if typing
what is the biological species concept definition
can produce fertile offspring and interbreed
what is speciation?
the process of one species giving rise to one or two more new species
how can speciation occur
when population becomes isolated from other populations of the same species due to living in a different area
once______ has happened they now can’t_____ ______, are reproductively ________ so they are two separate ______
speciation
breed together
isolated
species
what is the problem about distinguishing species
speciation is gradual, ability to interbreed declines gradually, there is no distinct stage between population and species, so it is arbitrary and subjective
individuals in species have the same number of chromosomes true or false
true
how many chromosomes do humans have
46
how many chromosomes do chimps have
48
what is it called when a centromere is at the end of the chromosome
acrocentric
what does acrocentric refer to?
centromere is at the end of the chromosome
what is it called when centromere is in the centre of the chromosome
metacentric
what is a hypothesis regarding chromosomes of evidence that humans and chimps share a common ancestor
chromosomes in pairs 12& 13 in a common ancestor fused to form the chromosomes in human pair 2
evidence for the common ancestor chromosome hypothesis (5)
- 12+13 combined= 2
- location of centromere in 12 matches in 2
- 2 has satellite DNA where 12’s centromere is- remanent?
-banding of 12 and 13 is the same as 2 - human 2 has telomeric DNA in the middle
evidence against the common ancestor chromosome hypothesis (2)
- length isnt perfect
- location of centromere in 13 doesn’t match
what is a karyogram?
image where all the chromosomes are arraned into pairs
karyotype
A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes.
what is a genome
all the genetic information in an organism
what are differences between DNA sequences that have a single base change called
SNP’s
single nucleotide polymorphism
what are SNP’s
differences between DNA sequences that have a single base change
because SNP’s are areas of difference, scientists use them to
determine ancestor or disease risk
genome sequencing is…
the process of determining the sequences of bases in DNA
in what ways do eukaryotic genomes vary
size and base sequence
prokaryotes, viruses and bacteria all have _____ genome sizes
small (generally)
comparison of genomesizes between humans plants
humans - 3 billion b.p long
japanese canopy tree- 150 billion b.p long
true or false, there is no link between genome size and organism complexity
true
things to take into account when comparing genome sizes
includes all DNA including non coding regions
plants can have polyploidy- have larger genomes
our view of complexity may be different
what is the next generation sequencing (NGS)
data entered into computers with programmes analysing info
what are the NGS computers analysing for
evolutionary relationships, personalised medicine
what is phylogenetics
classification of species based on evolutionary relationships- organisms are grouped based on common ancestry
what is this referring to: classification of species based on evolutionary relationships- organisms are grouped based on common ancestor
phylogenetics
